Most motorcycle engines are air cooled—heat generated from the combustion of the gasoline is transferred directly to the ambient air. In hot weather under heavy loads, the temperature of the engine oil can exceed recommended limits. For this reason, auxiliary oil coolers are frequently added. Oil flows through the oil cooler and heat is transferred to the ambient air. Auxiliary oil coolers typically comprise a finned heat exchanger and are typically mounted near the bottom of the engine. Unfortunately, there are several disadvantages associated with mounting an auxiliary oil cooler at this location. First, an auxiliary oil cooler mounted near the bottom of the engine is prone to damage from road debris. Second, the oil cooler often gets caked with dirt and grime which greatly reduces its efficiency in cooling the oil. Third, air flow to the oil cooler is blocked by the front wheel. And fourth, the oil cooler blocks air flow to the engine.
Some motorcycles, including the HARLEY-DAVIDSON SOFTAIL, HERITAGE, ROAD KING, ULTRA CLASSIC, and ELECTRAGLIDE models, contain engine guards. Engine guards, also known as crash bars, are metal tubes that attach to the frame and extend outwardly in front of the engine. They help prevent damage to the engine and may also help prevent injury to the rider's legs in the event of an accident.
Motorcycles with engine guards have been modified by adding fittings that provide communication between the interior of the engine guard and the oil reservoir of the engine. As the oil flows through the engine guard, some additional cooling takes place as heat is transferred to the ambient air. The additional volume represented by the interior of the engine guard also helps to reduce the temperature of the oil.
An oil cooler adapter kit is sold by J & P Cycles of Anamosa, Iowa on its website at www.jpcycles.com. The installation of the kit is an involved procedure best performed by a professional mechanic. Once installed, the oil cooler adapter kit routes engine oil through the engine guard. The adapter kit includes a thermostat that regulates the flow. Routing engine oil through the engine guard has little effect on the oil pressure.
Accordingly, a demand exists for an integrated motorcycle engine guard oil cooler that creates successive pressure increases and pressure decreases and that provides improved cooling.